The invention is in a lift chair, for physically challenged individuals, with arm rests that are pivotally adjustable to assist an individual in assuming a standing position.
Lift chairs for lifting physically challenged individuals from a sitting position to a standing position are well known. These chairs are generally well padded easy chairs with arm rest. The lifting mechanisms employed vary substantially. There are some lift chairs that manipulate the seat cushion only. Other chairs lift only the arm rests vertically upward. Lifting the arm rests only works for an individual that has substantial upper body strength. Moving the arms to a higher position helps a person lift his body onto his feet with his arms.
A more common lift chair has a chair frame that is pivotally attached to a support base. The chair frame is pivoted relative to the support base about an axis at the front of the chair and adjacent to the floor. A variety of power lift mechanisms have been employed to pivot the chair frame of these lift chairs relative to the base. The power lift mechanisms include rotatable screws and fluid cylinders. Some of the mechanisms are manually powered while others are electrically powered.
Pivoting a chair frame upward about a horizontal axis below the forward edge of a seat cushion causes the arm rests to pivot with the chair frame. The forward ends of the arm rests move forward and downward toward the floor. The rear ends of the arm rests move upward away from the floor and forward. At the same time a persons trunk is raise and moved forward relative to his or her feet. The end result is that the portions of arm rests that a person would push against with his hands to move to a standing position moves to an angle in which it slopes downward and forward and also moves away from his or her shoulders. In this arm rest position the use of a person""s arms and upper body to move to a standing position is rendered more difficult and less effective for many individuals.
Padded wide arm rests are difficult to grasp. A person with minimal grip strength may find it almost impossible to grip such an arm rest. When a padded wide arm rest is covered by a material with a relatively slick or smooth surface, a person with substantial grip strength may find that his hands slip on the arm rest rather than helping to lift his body to a standing position. The fact that the smooth surfaces of arm rests on some lift chairs also slope forwardly and downwardly makes it difficult for individuals, that rely on upper body strength, to move from a sitting position to a standing position.
The lift chair has a chair base. A chair frame is pivotally attached to the chair base for pivotal movement about a horizontal frame axis. The frame axis is positioned adjacent to a lower forward portion of the chair frame. A seat pad and backrest pad are connected to the chair frame. A linear actuator is connected to the chair base and to the chair frame for pivoting the chair frame about the horizontal frame axis between a seat pad lowered position and a seat pad raised position. Left and right hinge and ratchet assemblies have anchor arms fixed to the chair frame. Adjustable arms are pivotally attached to the anchor arms by hinge pins for pivotal movement about an arm rest axis. Each hinge and ratchet assembly includes a pivoted bolt that is engageable with a plurality of ratchet teeth to hold an adjacent arm in a selected position and to limit pivotal movement of an adjustable arm to a lower position. Bolt lockouts inactivate the bolts to permit pivotal movement of the adjustable arms to a lowered position. A left arm rest is attached to one of the adjustable arms with its rear end adjacent to the arm rest axis. A right arm rest is attached to the other adjustable arm with its rear end adjacent to the other adjustable arm.
The ratchet assemblies permit the arm rests to be pivoted to positions in which they are horizontal when the seat cushion is in a raised position. The arm rests can be used to provide assistance in moving to a standing position when the arm rests are in a raised horizontal position.